public async Task Handle_ActivityIdAndCardIdExist_SetsActivityOrderToNull()
        {
            var dbName = $"{nameof(MoveActivityToCardCommandHandlerTests)}_{nameof(Handle_ActivityIdAndCardIdExist_SetsActivityOrderToNull)}";

            using var context = TestApplicationDbContext.Create(dbName);
            var cancellationToken = new CancellationToken();

            var card1    = Card.Create("card1-title");
            var card2    = Card.Create("card2-title");
            var activity = Activity.Create("activity-title", 1);

            card1.AddActivity(activity);
            context.Cards.AddRange(card1, card2);
            await context.SaveChangesAsync(cancellationToken);

            var handler = new MoveActivityToCardCommandHandler(context);
            var request = new MoveActivityToCardCommand {
                ActivityId = activity.Id, CardId = card2.Id
            };

            await handler.Handle(request, cancellationToken);

            var activityFromDb = await context.Activities.FirstOrDefaultAsync(a => a.Id == activity.Id, cancellationToken);

            Assert.Null(activityFromDb.Order);
        }
        public async Task Handle_CardIdNotExists_ThrowsNotFoundApplicationException()
        {
            var dbName = $"{nameof(MoveActivityToCardCommandHandlerTests)}_{nameof(Handle_CardIdNotExists_ThrowsNotFoundApplicationException)}";

            using var context = TestApplicationDbContext.Create(dbName);
            var cancellationToken = new CancellationToken();

            var activity = Activity.Create("activity-title");

            context.Activities.Add(activity);
            await context.SaveChangesAsync(cancellationToken);

            var handler = new MoveActivityToCardCommandHandler(context);
            var request = new MoveActivityToCardCommand {
                ActivityId = 1, CardId = 1
            };

            Task <Unit> action() => handler.Handle(request, cancellationToken);

            await Assert.ThrowsAsync <NotFoundApplicationException>(action);
        }